Greg Bear's The Forge of God (1987)
Oh my god, I tried to read _The Forge of God_ years ago and couldn't even get through it. It was one of the few SciFi books I ever just set aside and gave up on. I think Greg Bear did _Blood Music_ which I liked, but his other stuff was too slow.
For giant space opera stuff like that, I prefer Gregory Benford _Tides of Light_ novels.
Enders Game is still a classic and I'll be happy that they try it in movie form, but I don't have much trust in Hollywood when it comes to turning books into Screenplays. The only time it seems to come out well is when the director or producer has a vested interest in the original story itself. _Alien_ and _Terminator_ are good examples of that.
Hollywood recently tried to turn _Jumper_ into a movie and they completely wrecked it. The book was absolutely fantastic, lightweight, imaginative and lively, but the movie somehow lost the fell of what personal teleportation would be like and what you could do with it. The book implied boundless freedom and possibilities for the characters, but the movie just lost itself in the standard hunter/prey conflict and special effects. Now it will probably never get done right and the possibility of that wonderful story being shown on screen has been lost.